COMPARATIVE ANALYSIS OF MEGAFLOOD DEPOSITS AND ALLUVIUM OF THE CHUYA AND KATUN’ RIVER VALLEYS (
Gorny Altai)
I.D. Zolnikov1,2, E.V. Deev3,2, D.V. Nazarov4,5, S.A. Kotler1
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia 3A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia 4Saint Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 119034, Russia 5A.P. Karpinsky Russian Research Geological Institute, Srednii pr. 74, St. Petersburg, 199106, Russia
Keywords: Суперпаводковые отложения, аллювий, эрозионные террасы, Чуя, Катунь, Горный Алтай, Megaflood deposits, alluvium, erosion terraces, Chuya, Katun’, Gorny Altai
Abstract
Sedimentary indicators of catastrophic glacial megafloods-plane-bedded angular gravel, cobbles, and boulders-are described in several sections of the high terraces of the Chuya River valley. The principal difference of these sediments from typical alluvium of this area is demonstrated. The clast roundness, grain size of clasts, and sedimentary structures of the high-terrace deposits of the Chuya and Katun’ valleys indicate the same facies originated through megaflood deposition. These results are at odds with ideas of alluvial, glacial, or glaciofluvial genesis of the high-terrace deposits of the Chuya River.
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